PHAIUS. 



745 



starch in 45 minutes; in about 91 per cent of the grains 

 and 99 per cent of the total starch in GO minutes. (Chart 

 D592.) 



The reaction with barium chloride begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 2 per 

 cent of the total starch in 5 minutes ; in about 3 per cent 

 of tbc grains and 8 per cent of the total starch in 15 

 minutes; in about 7 per cent of the grains and 11 per 

 cent of the total starch in 30 minutes ; in about 10 per 

 cent of the grains and 19 per cent of the total starch in 

 45 minutes; in about 16 per cent of the grains and 25 

 per cent of the total starch in 60 minutes. (Chart 

 D593.) 



The reaction with mercuric chloride begins imme- 

 diately. Complete gelatinization occurs in about 32 per 

 cent of the entire number of grains and 81 per cent of 

 the total starch in 5 minutes ; in about 59 per cent of the 

 grains and 91, per cent of the total starch in 15 minutes; 

 in about 74 per cent of the grains and 95 per cent of the 

 total starch in 30 minutes; in about 81 per cent of the 

 grains and 97 per cent of the total starch in 45 minutes; 

 in about S6 per cent of the grains and 99 per cent of 

 the total starch in 60 minutes. (Chart D 594.) 



Phaius hybridus (Hybrid). 



(Plate 27, fig. 138; Charts D 574 to D 591.) 

 Histologic Properties. 



In form most of the grains are simple and isolated, 

 with the exception of a few which appear in aggregates 

 of usually 2, rarely 3, components. Compound and 

 semi-compound grains usually of 2, rarely 3, components 

 are sometimes observed. The proportion of aggregates 

 and compound grains is larger than in either parent. 

 Well-defined pressure facets are not present. Most of 

 the grains are regular, but the irregularities noted in 

 both parents arc observed, though occurring with less 

 frequency than in either parent. The conspicuous forms 

 are ovoid, often elongated, with broadened and squared 

 distal margin; pyriform with broadened distal end; 

 pure ovoid; triangular with rounded angles; pyriform 

 with elongated, tapering, proximal end ; and club-shaped. 

 In addition there are curved-club-, bottle- or ten-pin-, 

 oyster-shell-, spindle-, boot-, urn- and knob-shaped, also 

 grains of indefinite shape. There are somewhat more of 

 the slender type than in P. grandifolius, but they are 

 much less numerous than in P. wallichii. The grains are 

 flattened, some much more than others, and when viewed 

 on edge are narrow ellipsoidal with distal end squared, as 

 in both parents. In form these grains are closer to P. 

 grandifolius than to P. wallichii. 



The hilum is of similar shape, but is more refractive 

 and more frequently demonstrable than in both parents. 

 A longitudinal, slit-like cavity is of about the same fre- 

 quency as in P. grandifolius, but less frequent than in 

 P. wallichii. While the hilum is usually unfissured, yet 

 fissures of slightly more varied character occur, and with 

 a little more frequency than in both parents. These 

 clefts in addition to arrangement found in both parents 

 are sometimes so placed as to form a soaring-bird figure. 

 The range of eccentricity is from about 0.16 to 0.024, 

 commonly about 0.08 to 0.05, of the longitudinal axis. 

 In the character of the hilum these grains are slightly 

 closer to those of P. wallichii. 

 24 .**», 



The lamella arc usually demonstrable throughout the 

 entire grain, but are often less distinct and finer near the 

 hilum as noted for both parents. The primary set have 

 about the same character and arrangement as in both 

 parents, with the exception that they are relatively 

 coarser in a larger proportion of grains. The refractive 

 border at the proximal and lateral margins is more fre- 

 quently present, and is of about the same width as in 

 P. grandifolius, but it is somewhat broader, as a rule, 

 and about as frequent as in P. irallirhii. Secondary sets 

 of lamellae are somewhat more frequent and often larger, 

 but commonly located as in P. grandifolius; but less 

 numerous, less often large, and less varied in location, 

 than in P. wallichii. The number may reach 153 on very 

 large elongated grains, and about 100 on the common 

 large-sized grains. In character and arrangement of 

 lamellae these grains are slightly closer to P. grandifolius, 

 but the numbers in both parents and hybrid are prac- 

 tically the same. 



The size varies from the smaller which are 6 by 4/i, 

 to the larger which are 150 by 48/t, in length and breadth. 

 The common size is about 74 by 38ft in length and 

 breadth. In size the grains are closer to P. grandifolius. 



Polariscopic Properties. 



The figure is usually very eccentric, although there are 

 more of the less eccentric than in P. grandifolius, but 

 more of the very eccentric than in P. wallichii; the mean 

 is slightly less than P. grandifolius, and somewhat more 

 than P. wallichii. The lines are fine and intersect 

 obliquely, as in both parents; they are somewhat more 

 often bent and 'bisected than in P. grandifolius, but much 

 less than in P. wallichii. The proportion of double fig- 

 ures is somewhat larger than in both parents. 



The degree of polarization is high to very high (value 

 87), more of the latter than in either parent, and hence 

 the mean is higher than in them. There is about the 

 same variation in the different grains as in P. grandi- 

 folius, but much less than in P. wallichii. A variation 

 is frequently present on the same aspect of a given grain ; 

 found in a slightly larger proportion of grains than in 

 P. grandifolius, but less than in P. wallichii. 



With sclcnite the quadrants are well defined and 

 unequal in size as in both parents ; they are slightly more 

 irregular in shape than in P. grandifolius, but not nearly 

 so irregular as in P. wallichii. The colors show im- 

 purity from both ends of the scale, considerably more 

 with the greenish tinge and irridescence than in both 

 parents, making the mean of impurity slightly higher 

 than in either parent. 



In the degree of polarization, in the character of the 

 figure, and in the appearance with selenite, these grains 

 are closer to P. grandifolius. 



Iodine Reactions. 

 With 0.25 per cent Lugol's solution, the grains color 

 a moderate blue-violet immediately (value 43), not so 

 deep and less bluish than in P. grandifolius; near the 

 tint, but deeper than in P. wallichii; the color deepens 

 rapidly, becoming more bluish. There is greater varia- 

 tion in depth among the grains, with the mean slightly 

 lighter than in P. grandifolius; not so much variation, 

 with the mean deeper than in P. wallichii. With 0.125 

 per cent Lugol's solution the grains immediately color 

 a light blue-violet, not so deep as in P. grandifolius. 



